Chemical Compound Shows Promise Against Tuberculosis

The antibiotic R207910 works faster than current drugs against Mycobacterium tuberculosis which causes tuberculosis. (File Photo)

Happily, Andries said, the new compound has a particular advantage for those patients infected with both M. tuberculosis and the human immunodeficiency virus that causes AIDS. One of today's three standard TB drugs (the most modern of the three, rifampin, introduced in 1963) speeds the breakdown of several important AIDS drugs in the body, making simultaneous treatment for the two diseases difficult, but R207910 apparently does not.

R207910 is one of a new class of chemicals called diarylquinolines, several of which have been studied for their potential to block inflammation. A Johnson & Johnson scientist created R207910 by accident while trying to create a different diarylquinoline, Andries said, but it was saved for future study anyway.

When recent tests by the company indicated its potential against TB, the scientists there looked into how it works. They found that the compound throws a molecular monkey wrench into the cellular machinery by which the TB bacterium makes adenosine triphosphate, or ATP, the microbe's primary fuel.

That is a different killing mechanism than is found in any other antibiotic, and it explains why R207910 is just as effective against drug-resistant strains of M. tuberculosis as against conventional strains. Moreover, because the mechanism by which humans (and even most bacteria) make ATP is so different than that used by mycobacteria, the compound is expected to be very safe in people.

Volunteers had no significant side effects after taking a variety of doses over two weeks, Andries said, acknowledging that problems could arise with longer treatment.

The drug is not foolproof. Andries's team has already found that about one in every 200 million TB bacterium harbors a genetic mutation that allows it to live even in the presence of R207910. But that is a manageable level of resistance, experts said, as long as the new drug gets used in combination with others.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said the new compound looks very promising but warned against raising hopes too soon. "I'm generally a little skeptical about things like this until you get into humans," he said.

Fauci also warned that TB drug development poses notoriously difficult financial challenges, both because human studies must be large to prove efficacy and because those countries that need it the most are least able to pay for it.